Solve for $x$ : $8\sqrt{x} - 6 = 4\sqrt{x} + 9$
Answer: Subtract $4\sqrt{x}$ from both sides: $(8\sqrt{x} - 6) - 4\sqrt{x} = (4\sqrt{x} + 9) - 4\sqrt{x}$ $4\sqrt{x} - 6 = 9$ Add $6$ to both sides: $(4\sqrt{x} - 6) + 6 = 9 + 6$ $4\sqrt{x} = 15$ Divide both sides by $4$ $\frac{4\sqrt{x}}{4} = \frac{15}{4}$ Simplify. $\sqrt{x} = \dfrac{15}{4}$ Square both sides. $\sqrt{x} \cdot \sqrt{x} = \dfrac{15}{4} \cdot \dfrac{15}{4}$ $x = \dfrac{225}{16}$